Allergic and irritant conditions of the conjunctivae and sclerae are quite common and are treated with sympathomimetic amines applied locally to produce vasoconstriction of local blood vessels. Such irritation or allergies of the mucous membranes of the eyes may follow accidental introduction of foreign particles or may be part of the allergic manifestations of asthma, hayfever, and allergic rhinitis.
While there are a limited number of vasoconstrictive compounds available for treating irritation of the eye there are no compounds available for preventing irritation of the eye due to irritant and/or allergic conditions, that is there is no prophylactic treatment available.
I have discovered that tricyclic anti-depressants usually prescribed for ameliorating the effects of severe depression are prophylactically effective when applied topically to prevent irritation of the eyes upon exposure to irritant conditions. These tricyclic anti-depressants have little effect on the treatment of already irritated eyes, but when combined with known vasoconstrictors are effective for preventing future irritations while effectively treating present irritation.